Stuffing-box vent



2 1927. Aug Y R. c. ENYART STUFFING BOX VENT Filed Nov. 15, 1923 2 Shoal-Shut 1.

1, 3 1 Aug. 2, 1927. Q R. c. ENYART 6 737 STUFFING BOX VENT FiledNov. '15, 1923 2 Shuts-Shea}. 2

Patented Aug. 2, 1927.

UNITED STATES PATENT OFFICE.

RALPH C. ENYABT, OF CONNERSVILLE, INDIANA,.ASSIGNOR TO THE P. H. &; F. M. BOOTS COMIANY, OF CONNERSVILLE, INDIANA, A CORPORATION OF INDIANA.

STUITING-BOX VENT.

Application filed November 15, 1923. Serial No. 674,821.

The present invention relates to pumps and its general object is to prevent the leakage of fluid from the pressure side of the ump around an actuating member extendmg exteriorly of the pum casing. The invention is particularly app icable to pumps of the Roots or twin impeller, positive displacement type. Pumps of this type are extensively used as gas exhausters and as gas boostl0 ers. The gas may be taken into the pump at a pressure below or above atmospheric pressure but in either case it is discharged at a higher pressure. The rotatable impellers are nicely fitted within the casing but the avoidance of friction requires that there be a slight clearance between the ends of the impellers and the end walls of the casing. If gas is being discharged by the impellers at any considerable pressure some gas finds its way through the small clearances at the ends and sides of the impellers to the shaft journals and bearings and it has been difficult to prevent the escape of this gas from the casing, even though the impeller shafts be provided with stuffing boxes. The present invention is particularly useful in preventing such escape of as.

In the drawings, whlch illustrate a preferred embodiment of the invention,

Figure 1 is a broken vertical section of a pump embodying the invention.

Figure 2 is a section on the line 22 in Figure 1.

Figure 3 is a section on the line 33 in Figure 1, and

Figure 4 1s a section on the line 4-4 in Figure 1,

The pump illustrated comprises a casing 1 having an inlet opening 2 and an outlet opening 3. The casing is provided at its opposite ends with head plates 4 through which extend parallel shafts 5 carrying co-operative impellers 6. The shafts 5 are provided with timing gears 7, which are diagrammatically indicated in Figure 3 although structurally they are secured to the shafts 5 outside of the casing. The operation by which a measured quantit of gas is positively delivered through t 1e casing at each revolution of the impellers is well known. The shafts 5 are provided with stufling boxes where they extend outwardly through the head plates 4 of the casing. In the pump illustrated the shafts are provided with collars 8 surrounded by suitable packing 9,

which is compressible by glands 10 drawn in to bosses 11 formed in the head plates. A space is provided surrounding the shaft at the inner end of the packing 9. This is preferably accomplished by the use of a lantern ring 12 formed on its inner face with projections 13 contacting with the face of the head plate and serving to space the body of the ring 12 from such face, the outer face of the ring forming an abutment for the packing.

The head plate is preferably cored out to form a passage 14 communicating by ports 15 with the annular spaces formed by the lantern rings in the two stuffing boxes. The passage 14 is preferably straight as shown and may be formed with a plurality of ports 16, each of which opens into the suction side of the casing 1, although in other constructions they may be arranged to open in any manner to the suction side of the pump, while the ports 16 are located so that one at least is always open to the interior of the casing at the suction side of the pump regardless of the position of either or all of the impellers.

The head plate is also formed with a port 17 extending from the passage 14. to an ex terior portion of the casing where arrangement is made for its connection to or with a pipe 18. It will be noted in the drawings that the passage 14 is so formed in the head plate that the end walls of the passage are exposed or open to the atmosphere, but these openings are normally closed by plugs 19, and the port 17 also may be normally closed by a plug or valve in the pipe 18.

In operation of the pump, gas is drawn in through the inlet opening of the casing and discharged by the impellers at a higher pressure through the outlet opening of the casing. Although the ends of the impellers are closely fitted to the inner faces of the head plates of the casing some gas will find its way from the discharge side of the casing to the stufling boxes of the impeller shafts, especially if the pump is discharging gas at high pressure. Gas reaching the stufling boxes in this manner passes into the spaces surrounding the shafts formed by the lantern rings. These spaces, however, are constantly in communication with the inlet or suction side of the casing and consequently gas reaching these spaces will be drawn back into the casing and cannot escape even if the packof a casing having a head-plate and having an'inlet and auontlet, a p'air of parallel ing in the stufiing boxes isnot completely effective. In the course of time tarry deposits or other obstructions may form in the passages, 14 and theports communicating-with th'em. J'l he passages and. ports may be cleaned by blowing steam through them by means of a pipe 18, or blowing or si'abbing them out through the openings normally closed by the plugs 19. \Vhile I have shown and described a preferred form or embodiment of my invention it will be appreciated. that the essense of the invention maybe embodied in many structures bearing little similarity'to that illustrated and described, nevertheless coming Within the purview of my contribution; F or this reason I do not desire to be limited in any manner to the embodiment shown anddescribed, but only bythe spirit of Iii'yinventi'on andthe scope of the appended claims.

Having thus described I claim is '1. IIrpum'ps and the like, the combinationof a casing'h'aving an inlet and an outlet, a shaft ext-ending exteriorly of the easing, a pump member secured to the shaft within the casing, astuiling box surroundingtheshafflthe casing being formed with a: passage extending from the stalling box to the inlet side of the casing and the passage having an opening exteriorly of the casing, and means norm-ally closing the opening p a 2. In pumps andthe like, the combination of a casing having. a,.liead-plate and having an inlet and an outlet, pair of parallel shafts extending throughithe headplate, cooperative impellers respectively securedto the'sliafts within the casing, and

my invention, What stufiing boxes surrounding the shafts, the

head-plate being forn'iedwith a gas passage connecting the stalling boxes and opening into the inlet side of the casing.

3. In pumps and the like, the combination of a casing having a head-plateand having an inlet and an outlet, a pair of parallel shafts extendingthrough the head-plate, cooperative impellers respectively secured to the shafts within the casing, packings re spectively: surrounding the shafts, and lantern rings res'pectively surroundi 'ig the shafts at the inner ends of the packings, the head-plate being formed with a; passage extending between the-lantern ringsand opening into the inlet side ofthe casin Y i 4. In pumps and'the like, the combination shafts extending lthrough thehead-plate, co-

operative impellers respectively secured to w the shaftsYwith-in 'c asi'ng,stutfing boxes I surroundin' rth'e shafts, the lieadsplate being ..;formed wit1apassage'connectingjthe stuf I y ingaacran impeller sha ft extending through fin g bases and having a plurality of open ings intothc inlet sideof the casing, the passage also having an opening exteriorly of the casing, and means normally closing the latter openin p 5. "In pumps and the like, in combination with a plurality of rotary cooperative impellers, acasing providing inlet and outlet ports arranged about said impellers and in cooperative piimping relation therewith, a shaft for each impeller journalled in journals in said casing, stnliing hoxcs providing recesses terminating.short of the interior of the casing in said journals, a lantern ring in each recess providingan annular space about each shaft, packing in said recesses andabutting againstthe exterior side of the lantern rings for sealingsaid recesses to the exterior, 'aiidconduits for receiving the gases leaking from the high pressure side of the casing and trapped in said spaces and adapted to convey such gases received to the lower pressure side ofthe casing.

6. In pumps and the like, in combination with a plurality of cooperative rotary impellers, a casing providing inlet an'doutlet ports arranged about said impellers and in coo )erative pumping relation therewith, a shatfor each impeller having a journal through said casing, a stulling box provid} mg a recess in each of said iournals,said

recesses terminating short of the interiorof' the casing, a lantern ring at the interior end of each recess and adapted to provide an annular space about each shaft adjacent the end of each recess, packing in each recess and abutting against the exterior side of the lantern rings for sealing-therecesses to the exterior, said spaces being adapted to rcceive and trap gases leaking from the high pressure side of the casing along the shafts,

a conduit connected with each of the spaces and having an openingto' the exterior of said casing, means connected. to the outer side of said casing and providing a substantially annular recess about said shaft, said recess terminating short ofithe interior of the casing, means in said recess secluding an interior portion thereof in aii tigh't 0cclusion from the exterior of the casing, a conduit having a, plurality of discharge orifices communicatingbetween aportion-of said recess andt-heintake-of the pump, said conduit having an orifice opening to the exterior of the casing and means normally closing said orific'e'in air-tight relation.

8. a pump construction having a casrecess and the intake of the pump, said con 10 duit and said portion of said recess each having an orifice opening to the exterior of the casing, and means normally closing said orifice openings in air-tight relation.

In Witness whereof, I hereunto subscribe l5 my name this 12th day of November, 1923.

RALPH C. ENYART. 

